| Causality constraints on gravitational effective theories |
| Julio Parra-Martinez, Caltech |
| Event Type: HEP Seminar |
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| Time: 2:00 PM - 3:00 PM |
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| Location: 726 Broadway, 940, CCPP Seminar |
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| Abstract: I will describe constraints from causality and unitarity on 2ā2 graviton scattering in weakly-coupled gravitational effective field theories. Together, causality and unitarity imply dispersion relations that connect low-energy observables to high-energy data. Using such dispersion relations, we can derive two-sided bounds on gravitational Wilson coefficients in terms of the mass M of new higher-spin states. Our bounds imply that gravitational interactions must shut off uniformly in the limit Gā0, and prove the scaling with M expected from dimensional analysis. In addition they demonstrate the gravity must be weakly coupled at all scales below Planck and that gravitational EFTs with a large number of light fields must have a low cutoff. Link to the Event Video |